Made the inbox icon on review request pages a shortcut for
archiving/unarchiving the review request.

The idea behind this change is to make the archiving/unarchiving of
requests a little bit faster for advanced users.

The shortcut was implemented by adding archive/unarchive click handlers
to the icon. A title attribute was also added to the icon which
dynamically changes to "Archive review request" or "Unarchive review
request". This should help with accessibility and general ease of use.

Testing Done

There were no changes made to any Python files so the Python tests were
not ran for this change.

The JS tests were ran for these changes.
These changes were implemented off the master branch version of
ReviewBoard which had 6 failures for the JS tests.

The JS tests when ran on this update had the same 6 failures as in the
master branch JS tests.